From telecom-request@delta.eecs.nwu.edu Tue Aug 22 16:18:18 1995 by 1995 16:18:18 -0400 telecomlist-outbound; Tue, 22 Aug 1995 12:08:16 -0500 1995 12:08:14 -0500 To: telecom@eecs.nwu.edu TELECOM Digest Tue, 22 Aug 95 12:08:00 CDT Volume 15 : Issue 351 Inside This Issue: Editor: Patrick A. Townson Book Review: "CDMA: Principles of Spread Spectrum Communication" (R. Slade) Billing Goofups (Gary Novosielski) Convert DID Voice System to ISDN BRI Voice System (Rick Strobel) CFP: 4th UK/Australian Int. Symposium on DSP (Tadeusz Wysocki) Telecommunications Short Courses (Bill Bond) TELECOM Digest is an electronic journal devoted mostly but not exclusively to telecommunications topics. It is circulated anywhere there is email, in addition to various telecom forums on a variety of public service systems and networks including Compuserve and America On Line. It is also gatewayed to Usenet where it appears as the moderated newsgroup 'comp.dcom.telecom'. Subscriptions are available to qualified organizations and individual readers. Write and tell us how you qualify: * telecom-request@eecs.nwu.edu * The Digest is edited, published and compilation-copyrighted by Patrick Townson of Skokie, Illinois USA. You can reach us by postal mail, fax or phone at: 9457-D Niles Center Road Skokie, IL USA 60076 Phone: 500-677-1616 Fax: 708-329-0572 ** Article submission address only: telecom@eecs.nwu.edu ** Our archives are located at lcs.mit.edu and are available by using anonymous ftp. The archives can also be accessed using our email information service. For a copy of a helpful file explaining how to use the information service, just ask. ************************************************************************ * * TELECOM Digest is partially funded by a grant from the * * International Telecommunication Union (ITU) in Geneva, Switzerland * * under the aegis of its Telecom Information Exchange Services (TIES) * * project. 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Any organizations listed are for identification purposes only and messages should not be considered any official expression by the organization. ---------------------------------------------------------------------- Communication" BKCDMASS.RVW 950526 "CDMA: Principles of Spread Spectrum Communication", Andrew Viterbi, 1995, 0- 201-63374-4, U$59.25 %A Andrew Viterbi %C 1 Jacob Way, Reading, MA 01867-9984 %D 1995 %G 0-201-63374-4 %I Addison-Wesley Publishing Company %O U$59.25 416-447-5101 fax: 416-443-0948 markj@aw.com tiffanym@aw.com %O 800-822-6339 617-944-3700 Fax: (617) 944-7273 %P 272 %T "CDMA: Principles of Spread Spectrum Communication" The use of a "spread spectrum", or multiple frequencies, for communication is known in some frequency-division multiplexed local area networks, and in some proprietary high-speed modems. Its use in wireless communications has historically been limited to the military, where the reliability and security in hostile environments have been worth the additional engineering. With the increasing use of, and interest in, mobile and cellular communications, code- division multiple access (CDMA) technology is quite desirable. As well as security, it offers much greater efficiencies of available bandwidth, location and velocity information, and improved "hand off" performance when crossing cell boundaries. Intended as a text for a graduate course in electrical engineering or communications, the book covers advanced topics in frequency reuse and bandwidth, synchronization, power considerations, interleaving and other topics. (Students are advised to keep texts from earlier courses as Viterbi does not always define terms or acronyms, and there are errors in the index.) While principles are outlined, the bulk of the book is devoted to detailed calculations of the practicalities of CDMA design. Chapter six is specifically devoted to the design of digital cellular systems. copyright Robert M. Slade, 1995 BKCDMASS.RVW 950526. Distribution permitted in TELECOM Digest and associated publications. Rob Slade's book reviews are a regular feature in the Digest. Vancouver roberts@decus.ca | "Metabolically Institute for Robert_Slade@sfu.ca | challenged" Research into slade@freenet.victoria.bc.ca | User rslade@CyberStore.ca | politically correct Security Canada V7K 2G6 | term for "dead" ------------------------------ > [TELECOM Digest Editor's Note: About twenty years ago I had a situation > such as you describe. I had a business line with an unusually high number > of local message units on it for about three months in a row. The phone > office serving that number had just about the same time been converted > to ESS. I had almost a mirror image experience to yours on my residence line about the time our local central office cut over to ESS in the early '80s. I suddenly *stopped* getting long distance charges altogether. Calls to numbers within my home NPA (201) got billed as usual, but anything with a foreign area code simply didn't show up on my bill. (This was before the "breakup," so everything was normally billed by New Jersey Bell regardless of destination. Still, something "different" about long-distance billing was clearly in place already.) I suspected something went wrong in the reprogramming of the new central office, but I didn't call NJB, since I was curious to see how long it would take for them to discover it on their own. I was careful to put aside the "savings" on the phone bill each month, since I was certain the day would come when they discovered the error and demanded payment. As the months dragged on, I found myself paying a little less attention to how long I stayed on the phone, or how many times I dialed an out-of-town BBS, but I didn't go nuts. Still, it was a full year before I got a "that call" at work from my wife. She said a nice lady from the phone company had called and started off the conversation with "Are you sitting down?" (always a bad sign) and had left a number. I called. It wasn't all that bad. My LD bill had run up to a tad over 700 bucks. I tried to sound surprised, but I don't know how well I did. It turns out, says the "nice lady," that when they reprogrammed the CO, my telephone number (let's say NNX-6147, was erroneously programmed to appear on the bill of a local business who had seven trunks beginning with 6140. Somebody added in their head and forgot to start counting with zero, it seems. She couldn't explain why my short-distance calls weren't affected. Anyway, the business hadn't noticed anything odd for a year, but finally questioned the numbers they were seeing, and got the phone company to discover their snafu and issue them a credit. I asked for and received a full listing of the calls, and sure enough they seemed to be familiar for the most part, but I figured it couldn't hurt to try and cut a deal with Telco. I called them and said that even though I couldn't remember every call I'd made for the past year, let's assume for the sake of argument that all the calls were mine. Did they expect me to just write them a check for 700 dollars? No, no, said the "nice lady." Since the billing error was their mistake, they were prepared to accept a small amount each month. How much? Oh, say, five or ten bucks tacked on to each bill. So we're talking about six to twelve years before they would recover the full amount, right? Um, yeah, she guessed that was right. Well, if she'd accept fifty cents on the dollar, I offered, I'd write her a check the next day, and we'd call it even, and what did she think about that? Well, she wasn't prepared to do the math in her head, but she was clearly familiar with the concept of Net Present Value, which rather precisely calculates what a bird in the hand is worth, in terms of birds in the bush, at a given interest rate (which back then would have been double digit). Uh, could she call me back in fifteen minutes? Sure. Three minutes later, the phone rang. She had talked to her supervisor, she said. And? And, just to confirm, I *had* said the $350 would be in the mail *tomorrow* right? Yup -- first thing in the morning, I assured her. "Done," she says. "Let me give you a post office box number to mail it to." And I haven't seen a billing error since. GaryN GPN Consulting gnovosielski@mcimail.com [TELECOM Digest Editor's Note: About 1976 I had a case similar to that. I was living in a building which had a switchboard for the tenants at the front desk and I decided to get my own personal phone installed as well. They put in my phone but never sent me a bill for anything, period, for about one year. Apparently plant never sent the paperwork to the accounting department saying the installation was complete. Since in those days we had a category of service where you got unlimited local calling (which is what I had ordered), provided there were no coin-rated calls on the bill (which I was careful to avoid) there was never any reason for anything to hit the accounting department out of the ordinary. Then one day some #$&^# phreak somewhere made a phraud thirty-party call and billed it to my number. Hmmm ... well of course the charges were forwarded to Illinois Bell from whatever telco was involved (or maybe it was intra- LATA all via Illinois Bell, I don't remember) and the end result was when the charges got into the system they 'fell out' for lack of an account to bill them to. Unbillable charges go into a suspense account and there are clerks whose job it is to be constantly cleaning out the suspense ledger and moving the charges to where they belong. This can be done by charging it back to the telco from which it originated, or by trying to investigate locally, etc. As part of the investigative process, if it is just a couple dollars or less then the clerks usually write it off on the assumption it costs more to do the paperwork charging it back to the other telco and arguing with the other telco about it ("you sent it to us"; "no we didn't, you must have gotten it from another telco"). And sometimes for whatever reason in those days the paperwork would get so mutilated and banged up they did not know where they got the charge from so they had to write it off. This time around, someone decided to dial the number and see if it was actually in service or not. Of course it rang; of course I answered. Bingo, that set off an audit with accounting making an inquiry of plant to see what the actual status of the line was. Plant reconstructed what paperwork they had on it and accounting had to turn on the service after the fact. Like yourself, I had been putting aside money for that day, and one day here comes a bill in the mail for installation charges and monthly service for about *one year* to date. Like yourself, I made a fuss about it, but not a very loud one. I mean, I knew what I was doing all along, so I had no legitimate gripe. I could have inquired about it a year before I did. They did however take off the phraud call which had been billed to me, and the supervisor got a big laugh out of the way things had all come together. PAT] ------------------------------ Could someone please help me find a solution to this problem: I need to replace DID circuits with ISDN BRI. Here's how my current system works: There are several DID trunks connected to an Exacom DID SF-200 interface box, which is connected to a Dialogic voice card on a voice mail system. There are 140 phone numbers assigned to the DID trunks. When a call comes in, the Exacom box signals the voice card and passes the last 4 digits of the phone number to the voice card. The voice mail system then answers, looks up the 4 digit number and then plays the associated greeting. The main problem is that DID circuits are very expensive in my area (the other, less important for now, issues include that DID is inbound only, and I feel that ISDN would be a better technology for the future). ISDN can provide the same functionality for 1/3 the monthly cost. Here's what I want: I want an ISDN device that will accept an ISDN line on one end and provide two analog phone lines on the other. The analog lines should be able to signal my voice card in the same way that the Exacom box does (in band DTMF). (If that is not possible I may be able to take the signalling info from a D channel via (maybe) a serial interface, that would provide the info out of band. But the former is MUCH preferred). Exacom said they were going to make a product like this in the future, the rep called it an ISDN to loop converter with DTMF. They did not provide a time-table, so I suspect it would be at least a year or more -- so I don't want to wait for them. If there's not an off-the-shelf product for this, I'd be interested in any tips on how I could build one myself. BTW, I've contacted all the vendors I could think of, and nobody seems to have anything remotely close. There were a lot of PRI devices, but not BRI. Can anyone recommend any products, vendors, etc that may be able to help me convert from DID to ISDN? Any and all advice is welcomed and REALLY appreciated. Rick Strobel InfoTime Fax Communications voice: 502-426-4279 fax: 502-426-3721 email: rstrobel@infotime.com ------------------------------ Systems 4th UK/AUSTRALIAN INTERNATIONAL SYMPOSIUM ON DSP FOR COMUNICATION SYSTEMS CO-SPONSORED BY: IEEE, CRC for BTN, IEE EDITH COWAN UNIVERSITY, JOONDALUP CAMPUS, PERTH, WESTERN AUSTRALIA SEPTEMBER 23-27, 1996 Communication System worldwide have provided a rapidly growing a useful services and are continuing to evolve using Digital Signal Processing. UK/Australian International Symposium was planned by a group of academics and professionals from both Australia and the UK to examine the plans for the future and the progress that has already been made in the field of DSP and their applications to communication systems. The organising committee of the symposium decided to hold the 4th UK/Australian Symposium on DSP for Communication Systems in Perth from 23 - 27 September 1996. A major objective of the symposium will be to pursue the progression from communication and information theory through to the implementation, evaluation and performance of practical communication systems using DSP technology. Papers are invited over the full range of Communication System, Communication Theory and Signal Processing. Examples of such areas are: Error Control Coding Modulation, Demodulation & Multiple Access Data Compression & Speech Coding Channel Characterisation Simulation & Modelling Synchronisation DSP Algorithms & Applications Information Theory Cryptography & Protocols Implementation Consideration Design & Analysis Paper will be reviewed on the basis of extended abstracts of about 1000 words. S e n d A b s t r a c t s t o: DR S H Razavi School of Electrical & Computer Engineering Curtin University of Technology GPO BOX U1987 PERTH WA 6001 AUSTRALIA Fax: 619.351.2584 Email: Razavi_SH@cc.Curtin.edu.au S e n d A b s t r a c t s from E u r o p e, A f r i c a and the M i d d l e E a s t to: Prof. B Honary School of Engineering, Computing & Mathematical Sciences Lancaster University LANCASTER LAI 4YR UK Fax: 441.524.594207 ·_ Email: B.Honary@Lancaster.ac.uk D e a d l i n e: Extended Abstract: 31 January 1996 Notification of Acceptance: 15 April 1996 Camera Ready Copies: 15 June 1996 I n q u i r i e s: All correspondence concerning the symposium organisation should be addressed to: Dr. T Wysocki CRC, Australian Telecommunications Research Institute Curtin University of Technology GPO Box U1987, PERTH WA 6001 AUSTRALIA Fax: 619.351.3244 Email: Tad@ATRI.Curtin.edu.au or T.Wysocki@cowan.edu.au O r g a n i s i n g C o m m i t t e e Prof. A Cantoni (CRC for BTN) Australian Telecommunications Research Institute Dr. H Razavi (CRC for BTN) Curtin University of Technology Dr. T Wysocki (CRC for BTN) Edith Cowan University Prof. B Honary (Lancaster University) United Kingdom Dr. H Eren (Electrical & Computer Engineering) Curtin University of Technology ------------------------------ Telecommunications Short Courses September - October, 1995 The University of Texas at Dallas Center for Continuing Education P.O. Box 830688, CN 1.1 Richardson, Texas 75083-0688 (214) 883-2204 ADAPTIVE SIGNAL PROCESSING IN TELECOMMUNICATIONS Adaptive signal processing algorithms are central to network echo cancellation, speech enhancement and acoustic echo cancellation (for hands-free teleconferencing and wireless communications), channel equalization, interference rejection in CDMA cellular, smart antennas, and active noise control. The course will give an overview of the Least Means Squares (LMS) and Recursive Least Squares (RLS) adaptive filter algorithms. It will focus on how these algorithms are used in the above telecommunications applications. September 11-12, 1995; 8:30 a.m. - 4:30 p.m.; UTD Conference Center; Instructor, Eric Dowling, Ph.D.; fee - $595, CEU's 1.4; for additional information, call Barbara Johnson at (214) 883-2204. MOBILE COMMUNICATIONS ENGINEERING In the past decade, the mobile communications industry has enjoyed an exponential growth in its customer base. This has forced many industries to respond to the demands of this exciting field. This course introduces engineers and other professionals to the basic elements of mobile communications engineering. Principle, practice, and system overview of mobile systems will be discussed. The main objective of this two-day course is not to provide an in-depth coverage of all the elements of this field, but to focus on the key elements, such as cell geometry, cochannel interference, modulation schemes, and channel effects. The key elements of TDMA and CDMA emerging digital cellular systems will be introduced. Subsequently, a comparison of these emerging systems in the face of channel impairments will be discussed in terms of the performance measures introduced in this course. September 15-16, 1995; 8:30 a.m. - 4:30 p.m.; UTD Conference Center; Instructor, Kamran, Kiasaleh, Ph.D.; fee - $595; CEU's 1.4; for additional information, call Barbara Johnson at (214) 883-2204. OBJECT-ORIENTED ANALYSIS AND DESIGN Object-Oriented Programming has become the methodology of choice in the 1990's. This course aims to equip students with knowledge of the principles of sound analysis and design techniques for programs that will be implemented in C++ or Smalltalk. Students will learn by experience as designs are formulated through the use of several case studies. The chosen methodology will mainly be based on Rumbaugh's OMT, although brief overviews of FUSION and Booch's methodology will also be given. September 21-22, 1995; 8:30 a.m. - 4:30 p.m.; UTD Conference Center; Instructor, Ivor Page, Ph.D.; fee - $595; CEU's 1.4; for additional informa- tion, call Barbara Johnson at (214) 883-2204. VIDEO DIAL TONE Video-based services, such as Video Dial Tone (VDT), are witness- ing rapid growth. This growth is likely to accelerate as some of the regulatory barriers faced by cable companies, local exchange carriers and interexchange carriers are removed by the Congress. In order to meet the higher bandwidth requirements of the video signals, telephone and cable companies are introducing new transport and switching technologies in the network. The stan- dards organizations such as ITU-TS and committee T1 and the ATM Forum are also defining new standards for handling video servic- es. This course is designed to bring students up-to-date with the market dynamics of the video industry and to provide techni- cal details, from data storage to different delivery architec- tures for the VDT services. September 25-26, 1995; 8:30 a.m. - 4:30 p.m.; UTD Conference Center; Instructor, Sudhir Gupta; fee - $595; CEU's 1.4; for additional information, call Barbara Johnson at (214) 883-2204. DESIGN OF FIBER COMMUNICATION SYSTEMS The design of high data rate/bandwidth short haul and long haul fiber communications systems is becoming important because of the high demand for large data rate/bandwidth transmission. Efforts are on the way to seamlessly connect the cellular networks to fiber networks whereby more services can be offered. This course introduces engineers, scientists and managers working in the telecommunications industries to the basic elements of fiber communication. Principle, design, practice and system overview of analog and digital fiber communication will be discussed. After completing the two-day course, the participants will have enough knowledge to understand, design as well as to evaluate digital and analog fiber systems. Design of 10Gbits/s digital systems, fiber communication for video transmission, wavelength division multiplexed systems, systems with concatenated fiber amplifiers, dispersion compensators and external modulators are some of the topics that will be discussed. The data rate impair- ments due to nonlinearity and methods to combat them will also be discussed. October 17-18, 1995; 8:30 a.m. - 4:30 p.m.; UTD Conference Center; Instructor, Lakshman Tamil, Ph.D., fee - $595; CEU's 1.4; for additional information, call Barbara Johnson at (214) 883-2204. Bill Bond bond@utdallas.edu ------------------------------ End of TELECOM Digest V15 #351 ******************************